Valve construction for pneumatic handling of granular materials



y 1966 M. J. BOZICH VALVE CONSTRUCTION FOR PNEUMATIC HANDLING OF GRANULAR MATERIALS Filed May 14, 1964 INVENTOR. SL J. BOZICH MICHA ATTORNEY L1 "Tm T Fig.8.

United States Patent 3,253,866 VALVE CONSTRUCTION FOR PNEUMATIC HANDLING OF GRANULAR MATERIALS Michael J. Bozich, 1059 Bayridge Ave., Pittsburgh, Pa. Filed May 14, 1964, Ser. No. 367,362 4 Claims. (Cl. 302-53) This invention relates to pneumatic handling systems for granular or powdered materials, and more particularly to an improved valve for transferring granular materials from a supply area to a receiving area.

While not limited thereto, the present invention finds particular utility in any pneumatic handling system where it is necessary to transfer, by gravity, granular materials from an upper chamber to a lower chamber or receiving area. As an example, one such system for pneumatically handling granular materials includes a pair of communicating hoppers, one disposed above the other, the upper hopper being open at its top to permit granular material to be poured into it, and the lower hopper being closed except for a material-receiving opening provided at its top and a material-discharge opening at its bottom. The discharge opening communicates with a pipeline or conduit through which the material in the lower hopper is conveyed to a storage place or the like by means of an air stream produced in the conduit.

The present invention is concerned with a valve mechanism for facilitating feeding or refilling of the lower delivery hopper with the material from the upper supply hopper. Such a valve mechanism includes a valve casing which interconnects the upper and lower hoppers. Within the casing is mounted a downwardly inclined valve seat and a plate-like valve adapted to close against the seat and shut olf the flow of material from the upper hopper. Preferably, the valve is pivotally mounted at its upper edge in the casing below, and adjacent to, the upper end of the seat. Mechanical means, such as a counterbalancing weight, is used to assist in swinging the valve upwardly toward its closed position against the seat. Also, an air supply line is fitted into an opening provided in the casing, and this opening is in approximate axial alignment with the lower face of the valve so that, when air is projected from the supply line through the opening, it drives against the valve face and swings the valve into a firmly closed position. The valve will thus remain firmly seated due to this stream of air driving against the valve, as well as to pressure created withinthe lower hopper due to air being forced therein.

From the foregoing, it will be appreciated that the valve mechanism is closed by creating a pressure differential between the upper and lower surfaces of the platelike valve, the pressure beneath the valve being greater than that above. While the system just described employs a positive pressure greater than atmospheric pressure, flap-type valves also find application in installations where a vacuum is created above the valve and atmospheric pressure is relied upon to seat the valve. For example, one such application is in cyclone separators where a partial vacuum is created within the separator itself to hold the valve in closed position. Ordinarily, the weight of the material at the bottom of the cyclone serves to periodically open the valve to permit the discharge of granular material, whereupon atmospheric pressure again closes the valve.

As an overall object, the present invention seeks to provide a new and improved valve construction of the type 'described above wherein a plate-like valve is adapted to close against a downwardly inclined valve seat positioned within a valve casing.

More specifically, an object of theinvention is to provide an improved valve seat for a plate-like valve construction. As can be appreciated, granular materials passing through such valves are highly abrasive in nature;

3,253,866 Patented May 31, 1966 and in the past the valve seat itself has usually been formed from sponge rubber.- The difficulty with a valve seat of this type, however, is that it has a very limited life and must be replaced from time-to-time.

Accordingly, the present invention provides a valve seat formed from soft gum rubber having a novel crosssectional area which enables it to be held within a slot in a downwardly inclined metallic frame while at the same time providing a tapered projection which abuts the valve itself, the arrangement being such that as the valve is pressed against the seat, it is compressed to provide a highly effective seal.

In accordance with another aspect of the invention, the valve itself is simplified over prior art constructions of this type in that it consists of a single integral plate having a first downwardly-depending planer portion adapted to be pressed against the valve seat and a second downwardly-depending planer portion bent in an acute angle with respect to the first portion, the valve resting on the tops of vertical posts at the intersection of the first and second portions for pivotal movement thereabout. With this arrangement, very little frictional resistance can be encountered between the valve and the posts as it pivots from its open .to closed position and vice versa.

The above and other objects and features of the invention will become apparent from the following detailed description taken in connection with the accompanying drla wlilngs which form a part of this specification, and in w 1c FIGURE 1 is a schematic illustration of a material handling system utilizing the improved valve construction of the invention;

FIG. 2 is a schematic illustration of a cyclone separator utilizing the improved valve construction of the invention;

FIG. 3 is a cross-sectional view of the valve assembly per se;

FIG. 4 is an end view of the valve assembly shown in FIG. 3, having the cover plate removed therefrom;

FIG. 5 is a plan view of' the valve seat backing plate of FIG. 3;

FIG. 6 is a cross-sectional view taken along line VIVI of FIG. 5;

FIG. 7 is a plan view of the valve seat gasket utilized in accordance with the present invention; and

FIG. 8 is a cross-sectional view taken along line VIHV-III of FIG. 7.

Referring now to the drawings, and particularly to FIG. 1, the granular material handling apparatus shown comprises a pair of hoppers v10 and 12 arranged vertically one above the other. As shown, the hopper 10 is provided with an open top to permit granular or powdered material to be poured therein. The lower hopper 12, designated as a delivery hopper, is provided with a funnelshaped bottom 14 having an opening 16 leading into a T-section pipe 18 which has its left end connected to a blower. 19 and its right end connected to a conveying conduit 21.

Interconnecting the hoppers 10 and 12 is a valve casing 20 having a plate-like valve 22 therein. The valve 22 forms the subject of the present invention and serves to control the fiow of granular material from hopper 10 into hopper 12. In the operation of thesystem of FIG. 1, granular material in the hopper 10 is permitted to'fall through the valve 22 into the hopper 12. Thereafter, valve 25 is opened and air from blower 19 is forced into the valve casing 20 through conduit 24 to close the valve 22, in a manner hereinafter described, while pressurizing the area above the granular material in hopper 12. At the same time, air is forced through the T-sect-ion pipe 18 in the direction of arrows 26 whereby the granular material falling through the opening 16 will be entrained within the air stream flowing through pipe section 18 and conveyed to the right as viewed in FIG. 1.

In FIG. 2, another arrangement utilizing the valve of the present invention is shown and comprises a cyclone separator 28 having a valve casing 30 secured to its open, lower end. Within the valve casing 30 is a valve 32 of plate-like form similar in construction to the valve 22 of FIG. 1. In the operation of the cyclone separator, granular material is fed therein through an offset pipe or conduit 34 while an exhaust blower, not shown, is connected to an outlet conduit 36. In this process, a partial vacuum is created within the cyclone separator, and since the conduits 34 and 36 are offset with respect to the axis of the separator 28, a whirling or rotational movement of the granular material will occur within the separator, the heavier material falling to the bottom of the cyclone separator while the lighter material is entrained in the gas stream and conveyed upwardly and out through the conduit 36. Thus, a partial vacuum is created within the cyclone separator, causing atmospheric pressure to close the valve 32 in a manner hereinafter described. When, however, a sufficient quantity of the heavier granular material collects at the bottom of the cyclone separator 28, the valve 32 will be forced downwardly to open the valve and permit the discharge of the heavier material.

With reference now to FIGS. 3 and 4, the valve 22 of FIG. 1 is illustrated in detail and comprises the outer rectangular valve casing 20. The outer casing 20 is provided With an inner, incline-d rectangular frame 38 welded or otherwise securely fastened to the inner faces of the casing. On one side of the casing 20 is an opening 40 which is normally covered by a housing 42 bolted or otherwise securely fastened to a flange 44 on the valve casing 20. Secured to opposite sides of the opening 40, as best shown in FIG. 4, are a pair of L-shaped brackets 46 each of which receives a threaded post 48 having a pointed upper end. The posts 48 serve to support, for pivotal movement, a plate-like valve element 50 having -a first downwardly-depending planer portion 52 adapted to be pressed toward the frame 38 and a second integral downwardly-depending planer portion 54 bent at an acute angle with respect to the first portion 52, the valve resting on the tops of the posts 48 at the intersection of the tfirst and second portions 52 and 54. In FIG. 4, it will be noted that studs 58 are welded or otherwise securely fastened to opposite sides of the valve element 50 on the inside surface thereof at the intersection of portions 52 .and 54, these studs serving as stops to limit the lateral movement of the valve element 50 on posts 48. It will be appreciated that the valve shown is extremely simple and economical in construction.

With reference, now, to FIGS. and 6, the frame 38 is shown in detail and has dovetail slots 60 milled in its 7 and 8, is a rectangular gasket 62 formed from gum rubher or the like. With specific reference to FIG. 8, the

cross section of the gasket 62 comprises an equilateral triangle in which two of its vertices 64 and 66 lie'within the dovetail slot 60. The remaining vertex of the equilateral triangle is truncated or fiat to provide a surface '68 against which the valve element 50 seats. It Will be noted that the surface 68 is of relatively small area. At th same time, when the upper surface of the valve elemeat 50 is pressed against the surface 68, the gum rubber gasket 62 will deform to a greater or lesser degree to form an extremely effective seal. Furthermore, the abrasive nature of the granular material conveyed through the valve will not materially interfere with the seating action, and the gasket will have good resistance to abrasion by such granular material.

With reference, again, to FIG. 3, it will be noted that the conduit 24 extends through the housing 42 and into the interior of the valve casing 20, this conduit being arranged to direct an air stream against the lower face of hopper 12, rotating the valve element 50 in a clockwise direction about the tops of posts 48. When, however, an air blast is injected through the conduit 24, the air impinging on the lower surface of the valve element 50 will cause it to rotate in a counterclockwise direction. In FIG. 3, it will be noted that the posts 48 are threaded and that the height of the posts is adjusted such that as the valve element 50 rotates, it does not engage or rub against the upper portion of the gasket 62. .Thus, there is no rubbing surface between the valve element and the gasket which can cause excessive wear. When the valve is fully seated, it is actually lifted off the tops of the posts 48 and suspended under air pressure against the gasket 62.

In the use of the invention in a cyclone separator such as that shown in FIG. 2, the conduit 24 is eliminated, the reason being that a partial vacuum is created within the cyclone separator which enables atmospheric pressure acting against the bottom surface of the valve element 50 to press it against the gasket 62.

Although the invention has been shown in connection with a certain specific embodiment, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

I claim as my invention:

1. In pneumatic handling apparatus for granular materials, a material supply hopper, a material receiving area beneath the supply hopper, a generally verticallyextending valve casing between the material receiving area and the supply hopper, an inclined downwardly facing valve seat in the valve casing, a plurality of generally vertical posts having pointed upper ends mounted in said valve casing at one side thereof, a plate-like valve pivotally mounted on the tops of said pointed end-s and having a first downwardly-depending planer portion adapted to be pressed against said valve and a second integral downwardly-depending planer portion bent at an acute angle with respect to said first portion, the valve resting on the tops of said pointed ends at the intersection of said-first and second portions for pivotal movement thereabout, and means for selectively creating a pressure differential above and below said valve seat with the pressure below being greater than that above to cause the valve to swing about the pointed upper ends of said posts into a firmly closed position against said inclined valve seat.

2. In pneumatic handling apparatus for granular materials, a material supply hopper, a material receiving area beneath the supply hopper, a generally verticallyextending valve casing between the material receiving area and the supply hopper, an inclined downwardly facing valve seat in the valve casing, a plurality of generally vertical posts having pointed upper ends mounted in said valve casing at one side thereof, a plate-like valve pivotally mounted on the tops of said pointed ends and having a first downwardly-depending planer portion adapted to be pressed against said valve seat and a second integral downwardly-depending planer portion bent at an acute angle with respect to said first portion, the valve resting on the tops of said pointed ends at the intersection of said'first and second portions for pivotal movement thereabout, and means for creating a vacuum in the material supply hopper whereby atmospheric pressure will cause the valve to swing about the pointed ends of said posts into firmly closed position against said inclined valve seat.

3. In pneumatic handling apparatus for granular materials, a material supply hopper, a material receiving hopper beneath the first-mentioned hopper, a generally vertically-extending valve casing between the material receiving and supply hoppers, an inclined downwardly facing valve seat in the valve casing, a plurality of generally vertical posts having pointed upper ends mounted in said valve casing at one side thereof, a plate-like valve pivotally mounted on the tops of said pointed ends and having a first downwardly-depending planer portion adapted to be pressed against said valve seat and a second integral downwardly-depending planer portion bent at an acute angle with respect to said first portion, the valve resting on the tops of said pointed ends at the intersection of said first and second portions for pivotal movement thereabout, and an air supply conduit connected to the valve casing at a side thereof to supply a velocity stream of air to said material receiving hopper, said air supply conduit being positioned to direct the air stream against the lower face of said first planer portion of the valve to swing it about the pointed upper ends of said posts into firmly closed position against said inclined valve seat.

4. In pneumatic handling apparatus for granular materials, a material supply hopper, a material receiving area beneath the supply hopper, a generally vertically-extending valve casing between the material receiving area and the supply hopper, an inclined downwardly facing valve seat in the valve casing, said valve seat comprising a generally rectangular inclined frame and a gasket of resilient material secured to the lower surface of said frame, a plurality of generally vertical posts having pointed upper ends and mounted in said valve casing at one side thereof, a plate-like valve pivotally mounted on said pointed upper ends, mechanical means urging the valve upwardly toward closed position against said gasket, and means for selectively creating a pressure differential above and below said valve seat with the pressure below being greater than that above to cause the valve to swing about the pointed upper ends of said posts into firmly closed I position against said gasket.

References Cited by the Examiner UNITED STATES PATENTS 1,363,354 12/1920 Rockwell 20--69 2,565,946 8/1951 Bozich 30255 HUGO O. SCHULZ, Primary Examiner.

ANDRES H. NIELSEN, Examiner. 

1. IN PNEUMATIC HANDLING APPARATUS FOR GRANULAR MATERIALS, A MATERIAL SUPPLY HOPPER, A MATERIAL RECEIVING AREA BENEATH THE SUPPLY HOPPER, A GENERALLY VERTICALLYEXTENDING VALVE CASING BETWEEN THE MATERIAL RECEIVING AREA AND THE SUPPLY HOPPER, AN INCLINED DOWNWARDLY FACING VALVE SEAT IN THE VALVE CASING, A PLURALITY OF GENERALLY VERTICAL POSTS HAVING POINTED UPPER ENDS MOUNTED IN SAID VALVE CASING AT ONE SIDE THEREOF, A PLATE-LIKE VALVE PIVOTALLY MOUNTED ON THE TOPS OF SAID POINTED ENDS AND HAVING A FIRST DOWNWARDLY-DEPENDING PLANER PORTION ADAPTED TO BE PRESSED AGAINST SAID VALVE AND A SECOND INTEGRAL DOWNWARDLY-DEPENDING PLANER PORTION BENT AT AN ACUTE ANGLE WITH RESPECT TO SAID FIRST PORTION, THE VALVE RESTING ON THE TOPS OF SAID POINTED ENDS AT THE INTERSECTION OF SAID FIRST AND SECOND PORTIONS FOR PIVOTAL MOVEMENT THEREABOUT, AND MEANS FOR SELECTIVELY CREATING A PRESSURE DIFFERENTIAL ABOVE AND BELOW SAID VALVE SEAT WITH THE PRESSURE BELOW BEING GREATER THAN THAT ABOVE TO CAUSE THE VALVE TO SWING ABOUT THE POINTED UPPER ENDS OF SAID POSTS INTO A FIRMLY CLOSED POSITION AGAINST SAID INCLINED VALVE SEAT. 